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My new project

Posted: Sat May 19, 2012 10:30 am
by charlesb
EBike1.jpg
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Hello all
Here is the start of my latest project. Original bike was a Kawasaki ZR250. Fitting a Mars ME0907 brushless motor, and there is a set of 48v 60AH lifepo4 batteries and BMS coming from Elite Power Solutions, which should be here next week.
As soon as the batteries come, I can get on with making the battery frame, and then rebuild the bike frame around them.
I still haven't quite decided on the controller. It will probably be a Kelly unit, and go for a heavily overrated model. I would like a Sevcon, but the programmer/software is a rip off and too complicated, shame really as their office is just local in Newcastle upon Tyne. Has anyone here had any recent experience with Kelly controllers? I know I am a bit limited being a brushless system.

Re: My new project

Posted: Fri May 25, 2012 11:27 am
by PHEV
Hi,

Weve had a lot of problems with Kelly on other brushless motors, but they do sell the Mars motor themselves so I imagine it is the only motor the controller is actually tested on at the factory. It's probably your cheapest and easist option - though don't expect it too be trouble free!

The Sevcon is a far superior controller, and you don't need to buy software or the handheld programmer. You DO however need an IXXAT can cable to connect too it and these are pricey. I would imagine however that someone may already have a profile ready for this model of motor - I may be able to help get a copy for you if you go ahead with this route - I know someone who works with them both (in fact, I could even program it here for you for a small fee to save you buying a cable).

Steve
jozztek.com

Re: My new project

Posted: Fri May 25, 2012 7:35 pm
by charlesb
Steve

Thanks for the info. I will probably go with a Kelly controller to start with. As you say, they sell this motor as a package. It looks like a simple unit to get the hang of programming, and if I kill it, it's not too expensive. I've heard it makes a bit of noise at low revs, I assume it's not sinusoidal.
My batteries and charger have arrived from Elite. They look well made, and all the voltages were the same at 3.3v I'm just waiting for the BMS to arrive from the U.S. while I get on with making the battery cage.

Regards
Charles

Re: My new project

Posted: Sat Jun 23, 2012 4:21 pm
by charlesb
Well its starting to go together. I've bent and welded up the new front frame, and the batteries are nearly fitted. Then it's on with the wiring. RS do good heatsinks with Tee slots, so I've used one as the base for the controller assembly. The 48 to 12v dropper is mounted there as well. I've got a E-stop isolator which I'm going to mount where the fuel filler was. I've cut the base out of the tank to make the electrics cover.

Hope to have the motor turning soon..

Regards

charles

Re: My new project

Posted: Sun Jun 24, 2012 7:12 pm
by Beemer
Looking real good!

Hint.
Don't forget keep in mind the handling of a bike matters most with torsional stiffness. :wink:

Re: My new project

Posted: Sun Jun 24, 2012 9:49 pm
by charlesb
Hi Beemer

I have been thinking about this. I put in an additional brace across the bottom, which the original frame did not have, but I would like to see if I could fit a diagonal cross brace in somewhere. There is a gap between the batteries and motor. I could also brace between motor mount and top tubes The original engine wasn't structural, but it would have provided some torsional strength.
I'm going to build it all up for testing and then strip for painting at the end, so any mods will be no problem.

Regards

Charles

Re: My new project

Posted: Sun Jun 24, 2012 10:12 pm
by Beemer
Hey Charles.
There's a guy called Tony Foale. A bit of a bike/frame tuning engineer.

http://www.tonyfoale.com/Articles/Frame ... waMods.htm.

Not only the front. I'd be tempted to bracket your frame for bolt on crash bars to stiffen on the sides in case you drop it. They would be bolt on and an X shape.

I made a single wheeled trailer for my bike and before then had forgotten how important torsional stiffness was. All is ok now but the first run to 20mph was scary as it shook me, my unbendable BMW R1100GS and the handlebars like a demon!

Re: My new project

Posted: Mon Jun 25, 2012 6:27 am
by mattcarr
Nice work there Charles.

What sort of BMS have you got on your battery pack?

Re: My new project

Posted: Mon Jun 25, 2012 10:15 am
by Beemer
mattcarr wrote:Nice work there Charles.

What sort of BMS have you got on your battery pack?

Maybe he will be of the Jack Rickard school. Bottom balance and never overcharge?

Re: My new project

Posted: Mon Jun 25, 2012 7:00 pm
by charlesb
That's a good idea Beemer, I was going to make side protection bars because, as you can see, the batteries are very vulnerable, so a X config would be fine, and would also give a frame for the side panels.
Matt, the BMS is from Elite Power, and seems to work fine. It monitors under and over voltage and cell temp, and has cell balancing, with progressively reduced charge rates, controlled through the can bus, which I can connect with the Kelly controller as well. I'm thinking of recessing the display into the top of the tank.
I have cycled the batteries with a wirewound heater , and all good so far.